1. Field of the Invention
The present invention relates to vehicle-mounted apparatuses used in vehicles including a passenger car, a transportation car and, in particular, to a vehicle-mounted apparatus for identifying an identification tag attached to an article.
2. Description of the Related Art
In techniques for identifying articles, barcode recognition and optical character recognition (OCR) have been widely used. The barcode recognition is advantageous in that a tag attached to a surface of an article is inexpensive, but is disadvantageous in that a barcode reader is expensive and the amount of information included in the tag is limited. The OCR is used affordably, but it has a problem with the accuracy of reading. Recently, therefore, radio frequency identification (RFID) for identifying individual information from tags put on human bodies or articles by radio waves via antennas has commanded attention.
In the RFID having no built-in battery, tags that are composed of ID memory and communication circuitry, such as CMOS chips and small loop-antennas, are attached to articles. A reader emits radio waves (charged waves) to the tags so that the tags receive energy required for responses. The excited tags acquire, for example, electric power by electromagnetic induction and then transmit ID data. The reader that changes its mode to the receive mode after transmitting the radio waves to the tags reads the ID data, and recognizes ID information included in the tags. Examples of transmission of the RFID signals include an electrostatic coupling type, an electromagnetic coupling type, and a microwave type. In the microwave transmission that utilizes radio waves within a microwave band, a maximum communication range reaches 5 to 10 meters at present.
The application of RFID technology to merchandise control in the retail market is spreading fast. For example, reading product information, such as a producer country, a producer, a product name, and a serial number, from RFID tags attached to various articles by a reader is technically feasible already. In the near future, it is quite conceivable that RFID tags will be attached to all articles in the world. There is a technique for acquiring information about whether a passenger rides in a vehicle from an identification tag, such as an RFID tag, to confirm passengers' rides. (See, for example, Japanese Unexamined Patent Application Publication No. 2003-30707, in particular, pages 3 to 4, and FIG. 1.)
Various kinds of articles may be placed in a passenger space of a vehicle. In a general passenger car, for example, cigarette packs, lighters, precision devices, such as a camera, or a personal computer, pieces of media, such as a compact disc (CD), and a MiniDisc (MD), or food items, such as an alcoholic drink, or a carbonated beverage, may be placed. Leaving a dangerous article, for example, a lighter, in the passenger space may cause an accident, such as a fire. If an article, such as a precision device or a food item, is left in a passenger space of a parked vehicle under the hot sun, the article will be damaged, rotten, or burst. Moreover, bringing alcoholic drinks in a passenger space may be banned in countries or districts, such as the United States, having particular regulations.
For home-delivery vehicles or general transportation vehicles, all descriptions of articles may be placed in a vehicle (in a passenger space and a storage space). Keeping track of whether those delivery articles are placed in the passenger space and the storage space is a demanding task and consumes much time of working hours for delivery. The patent document exhibited above discloses only a technique for keeping track of passengers' riding and does not mention handling of articles according to location information or conditions of the vehicle at all.